Even though I personally understand why J.Kent said, "maybe" to Clark, I think it was a bad idea to have him do so. Going forward, it will often be compared to the infamous line (from Batman Begins), "I won't kill you, but I don't have to save you." Mark my words. My hope is that Kent's response was taken out of context specifically because some of the dialogue was truncated for the trailer.

It's not a major deal, but, it's something that could have been avoided.